Technical Field
The present invention generally relates to batteries and, more particularly, to the use of a thin carbon cathode in lithium-oxygen batteries.
Description of the Related Art
Lithium-ion batteries are prevalent in fields such as consumer electronics, automobiles, medical devices, and home energy storage. In a lithium ion insertion reaction, the number of lithium ions that can be inserted into a host cathode determines the amount of energy stored in the battery. As a result, a large cathode is needed to increase the storage capacity of the battery. There is therefore a limit to how small an effective lithium ion battery can be made while providing a useful energy density.
Lithium-oxygen battery chemistries have a higher gravimetric and volumetric energy density (e.g., about 3,213 Wh/kg and about 7,422 Wh/L respectively with respect to only cathode mass or volume) than one of the most commonly used cathode materials, LiCoO2 (e.g., about 1,095 Wh/kg and about 5,543 Wh/L respectively with respect to only cathode mass or volume). Lithium-oxygen batteries therefore present a path toward further miniaturization, decreasing the weight and volume of batteries without sacrificing energy capacity. However, existing lithium-oxygen battery implementations use large, porous cathodes that still impose a volumetric disadvantage for miniaturized applications.